1. The puzzle was so difficult that it seemed unsolvable.
2. The mystery surrounding the disappearance of the treasure remained unsolvable for years.
3. The complex math problem was deemed unsolvable by the students.
4. The crime was so meticulously planned that it seemed unsolvable to the detectives.
5. Despite numerous attempts, the conflict between the two countries remained unsolvable.
6. The riddle was so cryptic that it appeared unsolvable to everyone at the party.
7. The software glitch was unsolvable even after hours of troubleshooting.
8. The enigma of the ancient artifact remained unsolvable to archaeologists.
9. The ethical dilemma presented in the case was deemed unsolvable by the jury.
10. The intricate web of lies woven by the suspect seemed nearly unsolvable to the investigators.